4" x 4" container or cottage cheese carton with a few 1/4" holes in the bottom
light seed starting mix
Step 1: Planting and Sprouting
DO NOT WATER from the top. Set the container in a shallow container of warm water to allow water to be absorbed into the soil mix. This may take an hour or more. When the soil starts to look moist on top, remove the container from the water and set it aside to drain any excess water.
Insert the container into a clear plastic bag and fold the bag over to create a mini-greenhouse for the coleus. Place the closed bag in a warm, bright location but not in direct sun. You should have seedlings up in a week or two. When the seeds start to sprout you need to remove the container from the plastic bag or they may all die from damping off disease. This is a fungus that forms on the surface of warm, damp soil.
No direct sunlight, just a warm, bright location. Continue to care for the seedlings for another 5-6 weeks. The seedlings will be a little crowded for a while but just be patient.
Step 2: Transplanting Seedlings
Place about 1/2" of dry soil mix in the bottom of the cells or 4 or 6-packs. Very gently place a plant in each cell and fill the cells with soil. Grasp the seedlings by the leaves to avoid crushing the stems. Set the pack in a container of water until the soil has absorbed enough water that the soil surface is damp. Remove the pack and place it in a tray or other container in a bright location. No direct sunlight and do not over water.
If the larger plants start to get too tall you can snip off the tops and place the stems in water to root them for more plants. You can also root them in Perlite or damp sand. See my Instructable on rooting impatiens.
Don't worry about having 50 or more plants. Whatever you don't use will be appreciated by gardener friends. Take extras to work and mark them FREE. I'll bet they don't last the day.